So they're having formal meetings with a non-entity. What's the problem?
I assure you, they are deadly serious -- with an emphasis on the "deadly."
Imagine if Brits really and truly believed as an article of the Church of England that some day the boat that took King Arthur away will return and King Arthur will resume the throne and rule England justly and prosperously until the end of time -- and you have something close to this Shi'ite doctrine.
It goes like this: There has to be a blood descendant of Mohammed to both rule mankind politically and be his infallible link to God's Truth.
They had 11 such Imams (so they say) and when the 11th was killed by political opponents, his son the Twelfth went into hiding, waiting for the right moment to come out and rule & preach again.
It cannot be that he died, because then mankind would be left with no link to God, and God would never do that to mankind. Hence, he's still alive.
Nor can it be that he had progeny who would rule, or they would have come out of hiding, proven themselves to be his heirs, and ruled.
Therefore, the twelfth Imam is still alive. Q.E.D.